1. Field of the Invention
The present invention relates to a lock, and more particularly to a lock with a resettable combination, the resetting operation of which can be readily performed.
2. Description of Related Art
In general, there are various kinds of locks used on motorcycles and bicycles, such as a U-shaped lock, a cable lock and so on. Since the cable lock has a flexible construction and a convenient operation, it is popularly used by many riders. A conventional cable lock has a locking head and tapered end respectively coupled with corresponding end of a cable. The locking head defines a locking hole therein. The tapered end can be snappingly received in the locking hole to achieve a locking state. When the cable lock is to be unlocked, a user may use a key to open the cable lock. This kind of cable lock has a disadvantage that the cable lock can not be unlocked if the user loses the key. For this reason, a kind of combination cable lock has been developed. The combination cable lock can be locked and unlocked by adjusting a set of symbol provided thereon, without using a key. However, the existing lock has a drawback that an unlocking sequence of symbols of the lock are preset by the manufacturer and generally can not be changed. As a result, the security effect will fail if the unlocking sequence of symbols is known by a person other than the user. Therefore, a variety of forms of lock with a sequence reset function were developed to overcome the drawback as mentioned above.
FIG. 8 shows a sequence reset means provided in a conventional lock. The lock typically includes an extension means having a locating head and a locking head respectively coupled with two different ends thereof. The locating head has a tube extending therefrom. The locking head has a rod extending therefrom and receivably engaged with the tube. The lock further includes a spring and a set of selectors respectively and subseqentially mounted around the tube of the locating head. Each of the plurality of selectors has a rotatable ring with symbols, such as numerals marked thereon, a locating block, a drive block and a torsion spring combined for symbol selection. A drive plate 80 is rotatably mounted around the tube of the locating block. The drive plate 80 has a tongue 81 formed thereon which is operable to shift the locating blocks of the set of selectors. Then the sequence reset operation can be performed when the locating blocks are separated from the rotatable rings of the selectors. However, this method to reset the sequence of the lock need to use a tool to operate the tongue 81.
FIG. 9 shows an alternative conventional lock with sequence reset function. The lock utilizes a knob 91 to drive a set of selectors 90. The knob 91 has a tapered block 911 formed therein. When the knob 91 is operated, the tapered block 911 will abut and urge the selector 90 to separate a locating block 901 from a rotatable ring 902 thereof, whereby the rotatable ring 902 can be operated alone and adjusted to a desired position. After the adjustment of the rotatable ring 902, the locating block 901 can be engaged with the rotatable ring 902 again by turning the knob 91 to its initial position. Therefore, the lock can be locked and unlocked under control of a new sequence different to an original one preset by the manufacturer. However, this kind of lock has a disadvantage that the knob 902 may be operated accidentally due to its configuration.
The present invention provides an improved lock with sequence reset function to mitigate and/or obviate the aforementioned problems.